The present invention relates to a surveying operation guidance system for providing guidance for an operator, who engages in surveying operation, e.g. for determination of a survey setting point, etc.
In a surveying operation, e.g. in a survey setting operation, an operator who operates on a surveying instrument installed at a known point (hereinafter referred as “distance measuring operator”), measures a target position for an operator on a target side (hereinafter referred as “pile driving operator”), and provides guidance the pile driving operator to move to a survey setting point (pile driving point). The position of the target is set at the survey setting point, and a pile is driven. Thus, survey setting operation requires two operators, i.e. the distance measuring operator and the pile driving operator.
As the surveying instrument, a surveying instrument of prism measurement type, using a prism mounted on a pole as a target, is now widely used.
In the surveying instruments used for survey setting operation, there are a surveying instrument which projects a distance measuring light for measuring distance and a visible laser point light for indicating a collimating direction. A target plate is mounted on a pole to ensure visual confirmation of the laser point light. When the laser point light is projected to the target plate, the projecting point of the laser point light can be confirmed. When the laser point light concurs with a center of the target plate, it is considered that the center of the target is aligned with the collimating direction.
It is designed in such manner that a prism for measuring the distance is mounted on the target plate, and that the prism is aligned with the collimating direction under the condition that the laser point light is projected to the center of the target plate.
In the past, it has been practiced as follows: When surveying operation is performed by two operators, the operator on the target side confirms deviation in a left-to-right direction and in a top-to-bottom direction based on the position on the target plate where the laser point light is projected. The distance is confirmed according to flashing of the light. In case the projecting position is deviated from the center of the target plate, the target position is corrected.
Conventionally, the laser point light and the distance measuring light have been used. The laser point light has been used to indicate a position, and the distance measuring light has been used to measure a distance, and these lights have been projected in parallel to each other. The target comprises the target plate, which diffuses the laser point light so that the laser point light can be confirmed visually, and the prism for reflecting the distance measuring light. In recent years, new types of surveying instruments appeared, i.e. a type, in which the distance measuring light is projected in non-prism mode and the laser point light and the distance measuring light are projected coaxially, and a type, in which the distance measuring light also serves as a visible laser point light.
In case of the target, in which the laser point light indicates the position, the target is made of a semitransparent material, by which the laser point light is diffused and can pass through the target. When the laser point light enters and is diffused, the laser point light can be confirmed from transmission side. When the distance measuring light is reflected by retroreflection, the distance can be measured.
Also, in the case of non-prism distance measurement, the distance is measured by a surface reflection light from an object, for which a distance is to be measured, and a reflection light is required. In general, a light amount of the reflection light from the object is not much, and the measured distance is comparatively short in the non-prism distance measurement compared with the case of the surveying instrument using a prism. Because the laser point light can be visually confirmed when the laser point light is diffused and passes through, it is difficult to confirm when the transmitting light amount is low.
JP-A-11-83484 discloses a surveying instrument for performing survey setting operation by using a prism pole, on which a prism is mounted as the target. JP-A-10-221073 discloses a distance measuring device, in which a target comprising a target plate and a prism are used and a laser point light to indicate a collimating direction is used.